Can any one point me in the direction to help

Im mining datacoin. i have two GPU's.

RX 580 and a R9 280X

If i mine only with the R9 280X i get about 180CPD

If i mine only with the RX 580 i get 207 - 214CPD

However if i mine with both of them at the same time i get 160 on the R9 and 180-185 on the 580.


Any one know why im losing CPD on my GPU's. I've tried the CPU offload at 0,1 and 2. I have a I7 4770k

No matter what settings i change i cant seem to get the max from both GPU's if they are both mining at the same time.